Reference no: EM13178845
A student was asked to determine the percentage of the components of a mixture of potassium bromide(KBr), magnesium hydroxide, Mg(OH)2 and barium sulfate(BaSO4). The mass of the sample of the mixture used was 3.21 grams.
The student extracted the KBr from the mixture with water and filtered insoluble Mg(OH)2 and BaSO4 from the solution, containing the KBr. After evaporating the filtrate,the student recovered and dried the KBr and found it weighed 1.43grams.
The student treated the insoluble residue of Mg(OH)2 andBaSO4 with 3 M HCl, dissolving theMg(OH)2. The student then decanted the supernatantliquid containing aqueous MgCl2 from the involubleBaSO4. After drying the solid, the student recovered 0.58 grams of BaSO4.
The student next added 3 M KOH solution to the aqueous solution and Mg(OH)2 precipitated. After filtering the solution and drying the precipitate, the student recovered 1.10grams of Mg(OH)2.
1). Calculate the percent KBr in the mixture
2). Calculate the percent Mg(OH)2 in the mixture
3). Calculate the percent BaSO4 in the mixture
4). Write a chemical equation for the reaction of solid Mg(OH)2 and aqueous HCL
5). Calculate the percent recovery,using the total mass of substances removed.
6). Calculate the percent error for the speration of the components of the mixture.